The results of studying the static current-voltage characteristics of EuGa2S4:Er3+crystals at room temperature are presented. The mechanism of current passage in them is revealed. The height of the potential barrier at the metal-semiconductor interface (0.9eV), the relative permittivity of crystals (3.1), and the concentration of traps (7.14 1016 cm-3) were calculated, and the shape of the potential well for the electrons trapped in the traps was determined.

We synthesized a solid solution of Ca(Al_ x Ga_1 – x )_2S_4 activated with europium ions Eu^2+. The photoluminescence spectra and photoluminescence excitation spectra of the crystals at 300 K for x = 0.2 are measured. The dependence of the luminescence intensity on the temperature in the range of 10–300 K is investigated. Based on the experimental results, the redshift, the Stokes shift, the activation energy, and the lifetime of the Eu^2+ ions are determined.